Research Technical Report

Integrating Geospatial Technologies for Effective Resource Management

King, C., R. Kvitek, G.H. Greene, and N. Wright (March 2003)

Poster Presentation at the Sanctuary Currents Symposium, Seaside, CA

ABSTRACT

A pilot study to map the distribution of rockfish along the Monterey Formation outcrops off Del Monte Beach in Monterey, California was conducted using SCUBA sampling methods, remote sensing, and GIS technology through a cooperative, multi-agency effort. Reflective sonar (244 kHz) data were collected and processed to generate a shaded relief image, and acoustically different substrata were mosaicked and interpreted for construction of substrate maps. ArcView 3.2 was used to visualize these layers, and to plot a small sample of non-random transects ) that included SCUBA diver observations. The observations made were of rockfish abundance and estimates of rocky substrate within each 2-meter wide and 10-meter long transect. Two hundred thirty-five (235) fish, belonging to 11 species were counted in 21 transects completed by SCUBA divers in September 2000. Rockfish densities were spatially and qualitatively correlated with percent cover of rock within each transect. The overall density was estimated as 2.88 +/- 0.191 (S.E.) fish per 100 m2 in transects that consisted of primarily rocky substrate. Breaking down the 21 transects into two groups of rock percent cover, 80-90% and less than 80%, yields a density twice as high in the 80-90% group. The area of study is not under any fishing protection and potentially low densities may warrant a management plan to protect the stock that is left in the area. This suite of technology holds the potential to correlate fish assemblages with habitat type, make related predictions, and develop management strategies.